Ground Motions from the 7 and 19 September 2017 Tehuantepec and Puebla‐Morelos, Mexico, Earthquakes

Research Article| October 16, 2018 Ground Motions from the 7 and 19 September 2017 Tehuantepec and Puebla‐Morelos, Mexico, Earthquakes Valerie J. Sahakian; Valerie J. Sahakian aU.S. Geological Survey Earthquake Science Center, 345 Middlefield Road, MS 977, Menlo Park, California 94025, vjs@uoregon.edueNow at Department of Earth Sciences, University of Oregon, 1585 East 13th Avenue, Eugene, Oregon 97403. Search for other works by this author on: GSW Google Scholar Diego Melgar; Diego Melgar bDepartment of Earth Sciences, University of Oregon, 1585 East 13th Avenue, Eugene, Oregon 97403 Search for other works by this author on: GSW Google Scholar Luis Quintanar; Luis Quintanar cInstituto de Geofísica, Universidad Nacional Autónoma de México, Circuito de la Investigación s/n, Ciudad Universitaria, Coyoacan, 04510 Mexico City, Mexico Search for other works by this author on: GSW Google Scholar Leonardo Ramírez‐Guzmán; Leonardo Ramírez‐Guzmán dInstituto de Ingeniería, Universidad Nacional Autónoma de México, Circuito Interior s/n, Ciudad Universitaria, Coyoacan, 04510 Mexico City, Mexico Search for other works by this author on: GSW Google Scholar Xyoli Pérez‐Campos; Xyoli Pérez‐Campos cInstituto de Geofísica, Universidad Nacional Autónoma de México, Circuito de la Investigación s/n, Ciudad Universitaria, Coyoacan, 04510 Mexico City, Mexico Search for other works by this author on: GSW Google Scholar Annemarie Baltay Annemarie Baltay aU.S. Geological Survey Earthquake Science Center, 345 Middlefield Road, MS 977, Menlo Park, California 94025, vjs@uoregon.edu Search for other works by this author on: GSW Google Scholar Bulletin of the Seismological Society of America (2018) 108 (6): 3300–3312. https://doi.org/10.1785/0120180108 Article history first online: 16 Oct 2018 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation Valerie J. Sahakian, Diego Melgar, Luis Quintanar, Leonardo Ramírez‐Guzmán, Xyoli Pérez‐Campos, Annemarie Baltay; Ground Motions from the 7 and 19 September 2017 Tehuantepec and Puebla‐Morelos, Mexico, Earthquakes. Bulletin of the Seismological Society of America 2018;; 108 (6): 3300–3312. doi: https://doi.org/10.1785/0120180108 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search nav search search input Search input auto suggest search filter All ContentBy SocietyBulletin of the Seismological Society of America Search Advanced Search Abstract The 2017 M 8.2 Tehuantepec and M 7.1 Puebla‐Morelos earthquakes were deep inslab normal‐faulting events that caused significant damage to several central‐to‐southern regions of Mexico. Inslab earthquakes are an important component of seismicity and seismic hazard in Mexico. Ground‐motion prediction equations (GMPEs) are an integral part of seismic hazard assessment as well as risk and rapid‐response products. This work examines the observed ground motions from these two events in comparison to the predicted median ground motions from four GMPEs. The residuals between the observed and modeled ground motions allow us to study regional differences in shaking, the effects of each earthquake, and basin effects in Mexico City, Puebla, and Oaxaca. We find that the ground motions from these two earthquakes are generally well modeled by the GMPEs. However, the Tehuantepec event shows larger than expected ground motions at greater distances and longer periods, which suggests a waveguide effect from the subduction zone geometry. Finally, Mexico City and the cities of Puebla and Oaxaca exhibit very large ground motions, indicative of well‐known site and basin effects that are much stronger than the basin terms included in some of the GMPEs. Simple and rapid ground‐motion parameter estimates that include site effects are key for hazard and real‐time risk assessments in regions such as Mexico, where the vast majority of the population lives in areas where the aforementioned effects are relevant. However, GMPEs based on site correction terms dependent on topographic slope proxies underestimate, at least in the three cities tackled in this work, the observed amplification. Therefore, there is a need to improve models of seismic amplification in basins that could be included in GMPEs. You do not currently have access to this article.